Controlled current inverter system having semiconductor overvoltage protection

摘要

A controlled current inverter system including an inverter circuit having controlled rectifiers for supplying an output of variable voltage and frequency for application to a load; e.g., an electric motor, further includes a variable direct current power source for supplying electrical power to the inverter circuit. Protection against overvoltage conditions of the inverter circuit rectifiers is provided as a function of the inverter output voltage, current and the electrical characteristics of a load supplied by the inverter circuit. This protection takes the form of circuitry which anticipates a potential overvoltage condition and acts to reduce the output of the direct current power source and inhibit the firing of the rectifiers of the inverter circuit until such time as the potential overvoltage condition is eliminated.